Madhu,
Your question needs to be addressed in two parts. Part 1 is installing the audio gear at the dealer vs doing it in the open market. Given below is the reply I had posted in another thread, on a simmilar issue. I think there the dealer was giving the guy a 20k audio package for free. 20k based on dealers prices.
The gist is applicable to your case as well.
"I would never install any accessories at the dealer. I would put all accessories from the open market. You would get a better choice and it would be cheaper.
Can u list by item, make, model, exactly what he is giving you for 20k? Chances are what he is offering as 20k of goodies would only be worth 8-10k in the open market. Next factor in the fact that the dealer would have bought all these items in bulk so it prob cost him 4-5k. He is giving 4-5k from the margin he makes on selling the car to ensure that you dont buy your car from someother hyundai dealer.
When I bought my car, the model came with a factory fitted cd player and front components which the dealer claimed was worth 30,000. I knew that I was going to install a full audio setup so I told the dealer to remove the cd player / speakers and give me a discount of 30k. After a long argument and my threatening to cancel the booking, he agreed to take it out and give me a 5000 discount. That should tell you something. 
Just get the bare bones car from the dealer for all accessories use the open market. Just my 2 cents worth."
Part 2 is the actual selection of the system. I would be best if you bought and built your setup over 2-3 steps. You could spend 16K now another 15k in 3-4 months or whatever time period that works for you. This way each part of your setup, hu/speakers/amp/sub would be of good quality and you would enjoy it for years. It would take some time, but then Rome wasnt built in a day. 
The other way and what 95% of people do is to try and cram everything into the first purchase. With this option while you may get thngs in one go, the quality of each component in your setup will have to be lower.
So in summation you need to decide:
1. Dealer vs open mkt
2. Final budget
3. One step vs 2-3 to build the system.
Based on the above we can then offer some solutions.